No, Davies, Craig Thermal Switch (Part No. 0400 & 0401) must be mounted in the engine compartment near the radiator.

We offer other switches which can be mounted within the car cabin, these include part <0444, 0445, 0448, 0500 or 8002

The adjustable thermal switch thermostat is a temperature control device which senses the temperature of the coolant as it leaves the engine,radiator and turns on the electric fan(s) when cooling is needed. The thermal switch thermostat is adjustable through a wide range of temperatures by turning an adjustable screw located on the controller.

The probe from the 0444 can be used within the radiator fins measuring thermal air temperature or installed it into your water / coolant system.

The Digital Controller (Part No. 8002) is Davies Craig’s recommended method of operating all models of the EWP. However it’s not the only method of control.

If the EWPs are to be used in motor racing or drag racing, you can run the EWP continuously, due to the extreme amount of heat produced under those conditions. If your race engine runs too cold, upgrade to the Controller.

The EWP may be used with a Davies, Craig Thermal Switch (Part No. 0401) as an auxiliary pump. If the EWP is the only pump in the engine it should not be run with an on/off thermal switch like a radiator fan. Your engine needs some flow all the time or hot spots will form outside the cylinders.

When the ignition is first turned on, the Digital Controller will 'system check' the EWP and it will run the pump for approx 10 seconds. The Digital Controller supplies a six volt PWM- pulse width modulation, (10 seconds on – 30 seconds off) to the Electric Water Pump from a cold start until the engine temperature reaches 20◦C below the target (set) temperature. At this point the Digital Controller then supplies a PWM (10 second on – 10 seconds off) till 5C less, then the Controller will ramp up to full system voltage as and when required searching for and locking onto the target temperature.

• Electric Thermatic Fan/s will deploy at +3◦C above target temp.
• If the engine cools below the target temperature, the Controller will step back from full system voltage down to 6v if necessary and generally it will go back to pwm when highway cruising.

The Digital Controller will indicate when;

• The EWP® is running
• The target (set) temperature is reached
• The supply voltage is too high or too low 
• The EWP® is running at full supply voltage and is not holding the target temp (Thermatic Fan/s need to be turned on)
• There is no power to the EWP®
• If you wish, you can look at what the Controller is supplying the pump by connecting a voltmeter to the EWP® motor leads. But remember when the Controller is in PWM mode, the meter will flicker.

Major advances in the new Digital Controller:

•  Temperature settings are now electronic in that the SET temperatures are now easily set digitally at the touch of a button. 
• An automatic time-out has been built into the Controller to run the EWP to the target temp or for a maximum of 2mins after ignition OFF, to eliminate the effects of heat soak on engine shutdown. Generally the EWP® will run for less than 2mins because heat soak washes out in about 20 seconds.
• A suite of self diagnosis functions has been built into the Controller which will identify cooling problems enabling easier trouble-shooting.
• The Controller has a number of monitoring features to keep the user appraised of system operation conditions at all times e.g. Controller on, pump operation mode, cooling system temperature etc.
• A new option for mounting the temperature sensor into the top radiator hose is offered in lieu of placing the sensor wiring between the hose and housing or into the thermostat housing. Part no is 0409.
• The current carrying capacity of the Controller has been increased from 7.5 amps to 12 amps in conjunction with a significant weight reduction.
• A 'Test' function has been adopted which gives the user a visual warning -- on the Controller and remotely -- if a system problem is evident.

Yes, as you haven't connected/installed the EWP yet you will need to close the circuit on the EWP 'T' connector. This is simple, take the small led light supplied and secure one of each end into each of the 'T' piece pins. This will now send a signal to the Digital Controller that the EWP is ‘connected’ and the Controller will execute this function correctly, engaging the Thermatic Fans at 3°C above the 5 set/targeted temperatures you have programmed into your Controller.

The EWP & Fan Digital Controller (part no. 8002) is primarily designed to run the EWP with the added function to switch on and off your Electric Fan, which saves you the cost of having to purchase an additional electric fan switch. If you are not using our EWP then we would recommend against purchasing the EWP & Fan Digital Controller as you primary fan controller as you can't independently set the cut in temp for the fan. The EWP & Fan Digital Controller is programmed to switch on the fan at 3°C above the EWP temp setting. For a fan only application we would recommend using either our Mechanical (part no. 0401) or Digital (part no. <0444) Thermatic fan switch and wire direct to the battery so the fan will run on after engine shutdown.

The 0409 kit comes with adaptors to suit inside diameter hose size of 30-35mm, if you have 36-42mm inside diameter hose then you need to use the 2 rubber sleeves over the adaptor to allow for the larger hose which are included in your kit. If you have 42-51mm inside diameter radiator hose, you can contact us and we can provide you with larger rubber sleeves to accommodate your needs.

We do not keep records on each and every vehicles top radiator hose dimensions and therefore leave it up to the customer to measure their radiator hose size and advise.

Please check the wiring of the fan relay. The green wire with the black trace from the Digital Controller to the fan relay is a negative switching wire. Therefore from relay pin 85, this wire should be connected to the positive battery terminal either directly or through pin 30.

The adjustable thermal switch 0401 is a temperature control device which senses the temperature of the coolant as it leaves the engine, radiator and turns on the electric fan(s) when cooling is needed. The thermal switch ostat is adjustable through a wide range of temperatures by turning an adjustable screw located on the controller.

No, your old wire leads will cause the controller to play up it is not recommended to wire the leads to the ignition coil.

To get the controller to work, you will need to install new leads and use an ignition switched source.

This is dependant on the type EWP being used or your set up. The EWP Digital Controller can't handle the total current of 2 x EWP115 (and greater) in parallel however it will handle 2 x EWP80's. However if you run the second EWP115, EWP140 or EWP150 off the fan output through a relay it will run both, but the second pump will only switch on and off 3°C above the set point, not via PWM.

The Davies Craig Digital Controller will operate with most other billeted/bolt-on OR remote-mounted Electric Water Pumps currently marketed around the world. Check that the output (current draw) required by CSR pump does not exceed 12 amps. From our records the current draw for most CSR pumps is around 5.8 amps. Check the output of your unit before proceeding. Please ensure you use the temperature sensor supplied with the Digital Controller as this unit has a programmed resistance to function with this specific Controller.

We believe you may have your Digital Controller incorrectly wired. The black striped thin green wire from the controller is a negative input wire, it has to be connected to relay at pin 86 as per the diagram within the instructions. In order to cut-in the fan, the pins 85 and 30 from relay must be connected to Positive power source as per the instruction diagram.

Like a computer, the Digital Controller can be stored for lengthy periods and your settings will not be effected.

At worst, it would return to the default setting of 85 Degre

No problem extending the Thermal Sensor cable. Be sure to use the same gauge wire to ensure you don't upset the electrical resistance of your EWP engine cooling system. Please note, depending on the length of the extension, it could lead to a delay reading the actual engine temp.

Your EWP/Fan Digital Controller has an in-built memory, a micro-processor which, among other features, maintains your targeted/set temperature once you've programmed your setting into the Controller. This setting will not be lost. Your cut-off/battery isolator will not affect your temperature setting. Further, to check your set/targeted temperature you simply press the button when the unit is reconnected and/or you turn on the battery isolation switch and the temperature LED will advise you of this set temperature.

I would strongly recommend to relocate the EWP Controller sensor to the same location or as close as possible to the vehicles temperature sensor so the 2 sensors are both reading from the same location. It is not uncommon for temperatures in different zones of a cooling system to vary by 10-20 degrees C and this temperature difference between the two sensors may be what's causing all your issues. Relocate the sensor and if you still have issues please let us know.

When you first install any thermal switch, make sure you run the car engine up to temperature or at least 110°F before trying to adjust the temperature switch. Please use the instructions for the correct set up procedure. Should the fans still not come on after instructions have been followed, please contact customer services for further assistance.

The new LCD Controller, Part number 8002 is compatible with the old controller, part 8020 or 8000 & 8001. The connectors are compatible, plug and play essentially. The main feature of the LCD unit are more information on the screen as well as the ability to run 12 & 24 Volt systems, audible alarm, expanded temp range 60-100c. The unit comes out of the box with a default setting of 85 degrees.

Yes.

You will need to ensure your probe is 6mm to be compatible with the compression nut/body/olive assembly supplied with this kit.

Or, if you are going to install a Thermal Sensor Sender unit the thread in the nylon Adaptor is ¼” NPT and this needs to be compatible to your sender unit.

PLEASE MAKE SURE you DO NOT cut the Sensor / Probe wiring to shorten or extend while installing. This action interferes with the resistance signal to the control box and subsequently an 'err' message will appear.

The switch will be completely useless and not serviceable if you cut the wiring.

We suggest you wind up the wiring should you need a shorter the lead.

You can extend the power wiring then relocate the switch to a location where you would like the sensor fitted.

The short answer is YES, you can connect the fan into the stock wiring.

Just be mindful of the fuses used for the stock fans, these may need to be changed to suit the new fans.

Yes, you can use the A/C wire as a manual override by providing it with 12V from a switch.

There is a 10 second delay between fan 1 and fan 2, if the temperature is dropped to the shut off point in this time then fan 2 will not turn on for very long this is totally normal.

The 0444 is not designed to operate after the car is shut down, it can be wired in such a way to have it run for a period of time after the ignition is turned off but it requires added wiring and a time delay relay.

It is not necessary to run fans after engine shut off unless there is an electric pump providing coolant flow through the radiator otherwise you are simply cooling the same water/coolant in the radiator and it is not circulating.

The unit is powered by the ignition. To have the unit come on when the ignition is on (but engine not started) you need to connect the ignition wire of the unit to a positive source that is on when the ignition is on.

Do not wire the ignition line to any 12V source, if you connect the unit to the ignition coil, ECU/computer or any other load it will cause issues, like you’re having

I suggest wiring directly to the ignition source for the best results.

Part 0465 is designed to fully replace the temperature probe on the latest version of the Digital Thermatic® Fan Switch Kit - part 0444.

The new version has a bullet style connector in the temperature sensor wires that allows for the sensors to be swapped out if they get damaged, or changed to the threaded type.

If your unit has the bullet connector then you can simply pull the prob style sensor out and connect the 0465 into the connector.

If your unit does not have this connector then you will need to get part No. 0418 which is a brass fitting designed to hold the prob in the coolant.

When it comes to choosing a frequency, it really depends on your system, what it can handle and how you intend to wire it.

In general, low frequencies put less work on the control circuit but you sacrifice precise control at low speed and can also produce noise.

Higher frequencies give better control at low speed but can cause the control circuit to overheat and reduce life.

To choose the best frequency is really a trial and error process, once you have dialled in the frequency you control the speed on the pump by adjusting the duty cycle on the PWM signal.

**A reminder, we hold international patents for a Digital Controller that will manage the operation of the EWP® by varying the speed of the pump in response to the coolant temperature.8002

The function graph is only a guide for the operation on the controller and not a 100% accurate representation. 

The correct operation graph would be confusing to many customers. As we use PWM to control the pump speed there is a start up point (shown as 0V on the graph) and 100% speed (shown as about 13V)

The 6V of the pulse mode is the 50% full speed mark between the start point and 100%.

Meaning there can be a little difference in actual voltage readings. the voltage is not able to be accurate measured with a multi meter because of the PWM control method.

It sounds like it is constantly rebooting.

The cause is that you have wired the controller up incorrectly by wiring the ignition directly to the ignition coil and not an ignition switched source like accessories. To test simple wire the ignition directly to battery positive, if this solves the issue simply re-locate the ignition wire.

The reason that your having this issue is because the electronics of the switch draw power for the ignition wire so the voltage needs to be constant and stable.

The ignition coil is not always a constant voltage, and it pulses in relation to the ignition cycle (unsuppressed) meaning it is neither constant or stable.

This can also be the same or similar for the distribution block due to other loads on the system.

What is happening in your case is that the voltage is dropping and causing the unit to power down, this voltage drop happens every 3 seconds

You can always try running the ignition through a relay controlled by the distribution block to connect the unit to the battery. This should help filter the “noise” in the ignition wire

The 8002 Digital controller does not have a built in A/C override, however it can be achieved be wiring the fans as shown below.

Alternatively, you can use a 5-pin relay for the A/C override to switch pin 85 of the fan relays between the controller (coil not powered) and ground.

The connections for this would be. This does depend on the relay used

If it was professional installation, we suggest you take the unit back and get them to find / fix the issues (they may be able to re-pin a bad connection in the plug)

You need to check all connections are tight as vibrations can cause connections to become loose.

Main areas that would cause this are

• Ignition wire, also it CANNOT be connected to the ignition coil this could also cause the problem.
• Ground connection

Check all connections are solid (by manually bouncing/wriggling them quite vigorously) this needs to be done at the connection point not the plug. If any connections are loose, he needs to tighten them up.  

Check the earth connection and ensure it is in solid contact with bare metal and that the main battery earth is connected properly.

It would also be a good idea to check that no wires have been damaged or kinked.

If the above dose not find a solution, isolate the loom (by holding the loom tightly so it can’t move about 3” front the plug/control unit) and first test again by moving the whole unit.

If this causes the issue, check all wires are secure in the plug by pushing then into the connector.

If a replacement unit is needed, you will need to re-wire the entire setup without cutting and joining any wiring. If you are able to locate the exact cause, then it may avoid the need to replace anything. To isolate the part that needs replacing.

As a general rule on any Davies, Craig digital switches/controller with below issues: 

• Flashing display
• Constant resetting
• Any periodic behaviour E.G, problem happens every 3 seconds or similar

Check the ignition location, if it is connected to the ignition coil or another source that has a reasonable load on it could be the cause.

A simple test for this it to connect the ignition wire directly to battery positive, if it operates correctly then they need to relocate the ignition to an ignition switched source like the accessories.

We assume you are using our EWP/Fan digital controller, if not, then all our fan switches are not designed to run after ignition is turned off. This is because without coolant flow there is no point in running a fan as it does not provide any real benefits.

When wiring a digital controller up with a kill switch, as long as you wire up as per instructions meaning the power wires are connected directly to battery positive, the function will not be affected. The ignition wire is only a signal wire and power for the unit is taken form the battery. If you are required (by safety regulations) to have all system connected to the kill switch then the function will not run.

The overrun will only be affected when the kill switch is disconnecting the battery. This mean that if you want the overrun function to work, you just need to leave the switch closed until the controller fully shuts down. If the ignition is wired directly to battery positive without being switched by the ignition, then the unit will not preform the shutdown/overrun function as the ignition has a constant positive 12V signal.

Firstly, when the probe is installed in the fins of the core there will be a certain degree of temperature difference (we estimate 15 deg C ) between the coolant temperature and the fin/core radiant temperature. This difference is by no means an inaccuracy but it does need to be accounted for when setting and reading the unit.

But to answer your question: No, you cannot cut the temperature prob off and connect it to the sensor of your existing gauge doing this will likely result in errors that will result in the unit not functioning correctly.

The only way to fix these errors would be to replace the unit. If you wish to read the coolant temperature then you MUST use the temperature sensor adaptor kit (part 0409) to install the prob into the top radiator hose. This will allow you to read the coolant temperature rather than the ambient temperature of the core.

You are correct the system is operating exactly as it is designed. The problem with a thermosyphon car is that they generally don’t produce as much heat and the system has a quite small flow rate.

What I normally recommend for customers installing an EWP in a thermo syphon car is to install the EWP and fan and have both controlled by a 0444. When wiring the fan is wired to FAN1 and the EWP to FAN2. What this does is it runs the fan as required but if this is not enough then it switches the EWP on after 10 seconds.

This can further be improved upon with the release of the 0500 paired with the 0465.

The 0500 has independent set temperature allowing the system to be fine tuned to achieve the best cooling performance.

A way to allow the car to get up to temperature without needing to restart the can after 5 minutes is to install an 0401 on the controller’s ignition line and set it to as low as possible, what this does it creates a temperature-based time delay.

By doing this what happens it the 0401 keeps the controller off until the temperature reaches 40degC at this point the 0401 switches and the controller will turn on.

Using the EBP23 and the 8002 controller is not recommended as we cannot guarantee a usable flowrate at 6V.

This is because the start up voltage of the EBP23 is 5V so when running at 6V there may not be enough head pressure to move the water though the system.

We recommend using one of our switches to run the booster pumps such as part numbers 0401, 0444 or 0500

You can shorten the wiring on the Digital Controller excluding the sensor wire.

Our recommendation is that you wind up the wiring and not cut.

Regarding the sensor wiring: PLEASE MAKE SURE you DO NOT cut the Sensor / Probe wiring to shorten or extend while installing. This action interferes with the resistance signal to the control box and subsequently an 'err' message will appear.

We suggest you wind up the wiring should you need a shorter the lead.

The EBP25 (9025) cannot be used with the 8002 Digital controller as it requires a minimum of 8V before it will operate.

The use of an EBP23, EBP25 or EBP40 with the 8002 Digital controller is not recommended as we cannot guarantee any usable flowrate at 6V.

This is because the start-up voltage of the EBP23, EBP25 and EBP40 is around 5V so when running at 6V there may not be enough head pressure to move the water though the system.

We recommend using one of our Thermatic switches such as part numbers 0401, 0444 or 0500 to control electric booster pumps.

The ignition (yellow wire) needs to be connected to a switched positive source.

As long as the ignition is receiving a positive voltage the exact source (direct battery or elsewhere) should make little difference.

However, for positive earth vehicles we recommend that the ignition be wired direct to battery positive though an on/off switch.

The switch can be a battery cut off switch or an ignition controlled relay.

The 0444 will not need to be reset when disconnected from power.

If you are using the EWP as an Auxiliary Pump supporting and mechanical pump, you could connect the pump to the ECU and use the fan circuit which would turn the pump on and off with the fans.

If you are using the EWP as the main cooling pump and removing the mechanical pump, you will need the Davies Craig EWP Controller8002.

Yes, but in many cases this will provide no benefit unless your fans draw over 30A continuous, in which case a relay with a higher Amp rating can be used.

The relay socket on the switch is rated to 40A continuous draw, this will not be affected by the rating of the relay.

The start up current handling ability is rated at 60 Amps (same as our 16" Fan, part 0166) and has completed over 10,000 test cycles under these conditions.

It is also important to note that there are very few, if any fans on the marker that draw over 35A continuous.

This means that the standard relays included in our fan switches, part 0444 & 0445 are appropriate for the majority of electronic fans on the market without the need for modification.

We recommend installing the sensor anywhere on the hot side of the cooling system.

This can be the Thermostat housing, radiator or you can even utilise unused ports in the engine.

If you are not running a heater, you can always use the heater outlet from the engine to install the sensor.

The fan relay may not be wired correctly. This is because the controller triggers the fan relay on the negative side which is why you don’t get a signal from the fan trigger.

A quick test for the wiring is to unplug the controller and then jump the fan relay wire (Green and Black) to earth / negative. If the fans don’t come on, then you need to check that the fan relay wiring Exactly matches the diagrams in our instructions.

When the probe is installed in the fins of the core there will be a certain degree of temperature difference.

The exact temperature difference will vary depending on several factors, like ambient temperature, airflow and coolant flow through the radiator.

We estimate that there could be somewhere between 5 deg C  and  15 deg C  difference between the actual coolant temperature and the temperature of the radiator core.

This difference is by no means an inaccuracy but it does need to be accounted for when setting and reading the unit.

If you wish to read the coolant temperature directly, Then you can use 0445 or 0448 that include a brass sensor that can be installed into a port

We also have parts 0435 and 0438 that include an inline adapter that can be installed into the top hose.

No, it is not possible to invert the controller functions.

If you are able to do so, remove the thermostat and block off the thermostat bypass.

If you wish to keep your thermostat in place, you will need to drill 2 x 3mm holes in it so that there is continuous flow to the pump.

The most common cause is a bad connection or the main battery wire has been connected to a fuse that has blown (note: there should not be a fuse on the battery wire)

The easiest way to test all the wire is to do the below tests:

1. Remove both relays,
2. Using a multimeter or test light check that you have power at pin 87 or pin 30 of the relay
1. One should have power an on should not.
2. If you are not getting power at one of these then you are not getting battery power to the switch.
3. If you get power at one of these, then jump pin 30 to 37
1. When this is done the fans will be powered independent of the switch
2. If the fans do not turn on then I recommend removing all connections and just twisting the wires together to test
3. If the fan turn on with the wires twisted together then plug the relays back in and test again by connecting the green wire to positive power.
4. If the fans are still working, then carefully re do the fan wiring connections.

If this testing doesn’t come up with anything then the issue might be the switch.

Contact us directly for further assistance.